1. Field of the Invention
This invention relates to a mobile citizen band transceiver (hereinafter referred to as CB transceiver) control unit with an audio frequency apparatus such as a radio receiver, and more particularly to a mobile CB transceiver control unit with an audio frequency apparatus which can be easily and surely operated by an automobile operator.
2. Prior Art
There has hitherto been proposed use of a mobile amplitude modulated (hereinafter referred to as AM) band and/or frequency modulated (hereinafter referred to as FM) band radio receiver as a mobile audio frequency apparatus. The channel is selected by push buttons, or by manual or automatic tuning. Some mobile radio receivers are equipped with a tape cartridge player/recorder in which audio information can be reproduced from or recorded on a magnetic tape.
FIG. 1 shows one example of a conventional mobile radio receiver. It is an AM/FM multiplex five push button type radio receiver. A housing 1 contains a tuning circuit for channel selection, an AM/FM detecting circuit, a low frequency amplifier and so on. An AM/FM change-over slide switch 3, channel selecting push buttons 4 and a dial plate 5 are arranged in a nose escutcheon 2. At the right side of the nose escutcheon 2, a tuning knob 6 and a stereo control knob 7 are arranged concentrically with each other. And at the left side of the nose escutcheon 2, a power switch-volume control knob 8 and a tone control knob 9 are arranged similarly concentrically with each other. An antenna lead socket 10, speaker connection leads 11 and 11', and a power supply lead 12 are connected to the back side of the housing 1.
FIG. 2 to FIG. 4 show the manner in which the radio receiver RX as above described is mounted in an automobile. The manner is called "In-dash type of mounting". FIG. 2 is a forward view from the rear seat. And FIG. 3 is a cross-sectional view of a part of the autombile.
As shown in FIG. 4, a rectangular opening 16 and round openings 17 and 18 are made in an instrument panel 15 for receiving the nose escutcheon 2 and the shafts of the tuning knob 6, the stereo control knob 7, the power switch-volume control knob 8 and the tone control knob 9, respectively. As shown by FIG. 3, the radio receiver RX is fitted to the instrument panel 15. In the in-dash type of mounting, only actuating members such as the knobs and indicating members such as the dial plate 5 appear at the front of the instrument panel 15 in the radio receiver RX. Some vehicle instruments 19, 19' and 19" are also fitted to the instrument panel 15. Such in-dash type of mounting has the advantage that the driver can easily operate the radio receiver RX. Moreover, a storage section 20 is arranged in the instrument panel 15. An engine compartment 22 is separated from a driver compartment 23 by a partitioning wall 21.
FIG. 5 and FIG. 6 show the other manner in which the radio receiver RX is mounted in the automobile. The manner is called "Under-dash type of mounting". In FIG. 5 and FIG. 6, the parts which correspond to the same parts in FIG. 2 and FIG. 3 are denoted by the same reference numerals.
The openings for fitting the radio receiver RX are not made in the instrument panel 15, in the under-dash type of mounting. The radio receiver RX is fixed by metallic members 25 and 26 under the instrument panel 15, as shown by FIG. 6. The radio receiver RX is hung from the instrument panel 15. Such under-dash type of mounting has the disadvantage that the operator has difficulty operating the radio receiver RX since it is somewhat remote from the operator and that the radio receiver RX is apt to be struck by the knee of the operator or any vehicle passenger.
Recently, it has become popular to mount a CB transceiver together with the above described radio receiver in automobiles. By the CB transceiver, audio signals are transmitted and received between the driver and any other person having a CB radio. Mainly, an AM modulating method or SSB (single side band) modulation method is employed for the CB transceiver. And the frequency band of about 27 MHZ is employed for the CB transceiver. No special license is required for the operation of the CB transceiver. Accordingly, the CB transceivers are widely used between general citizens.
FIG. 7 shows one example of a CB transceiver which is not for an automobile, but for general use. A housing 28 is substantially as large as the housing of the radio receiver, and it contains a high frequency amplifier for transmitting and receiving CB signals, a channel selecting circuit, a modulating circuit, a power amplifier and so on. A channel selecting knob 30, a channel indicator 31, a fine tuning knob 32, an illuminating lamp 33, a level meter 34, a volume control knob 35, a power switch 36 and a microphone socket 37 are arranged in a front panel 29 of the housing 28. And an antenna lead socket 38 is arranged in a side panel of the housing 28.
When the CB transceiver as above described will be mounted in the autombile provided with the radio receiver, it is necessarily mounted under the instrument panel 15, namely in the under-dash mounting manner. Because the instrument panel 15 is limited in surface area, and different leads and pipes are arranged behind the instrument panel 15, both the radio receiver and the CB transceiver cannot be together assembled into the instrument panel 15. A housing which contains electrical circuits such as amplifiers both for the radio receiver and the CB transceiver, is so large-sized that the housing cannot be fitted to the instrument panel 15 in the in-dash mounting manner.
However, when the CB transceiver is mounted in the under-dash mounting manner, in the automobile, it is difficult for the operator to operate the CB transceiver, since it is far from the operator, and since the number of the channels in the citizen band is as large as 40. The operator is apt to misoperate the channel selector. Moreover, there is a serious problem with regard to the safety of the operator driving the vehicle while operating the CB transceiver. The CB transceiver is apt to be struck by the knee of the operator or any other vehile passenger. Since the CB transceiver mounted in the under-dash mounting manner can be easily dismounted from the automobile, it is easy to be stolen.